Is there anyone that has done a family tree on the Voy family?

Question:You might check 2 free sites, Rootsweb and FamilySearch.org.

Now just be very careful about taking as fact everything you see in family trees on any website, free or paid. Most of the information is not documented. You might see different information on the same person by different submitters. Then you will see repeatedly the same information by different submitters without documentation.
A lot of people are copying without verifying. Use the information as clues as to where to get the documentation.

I noticed on FamilySearch there were also some McVoy.

Best Answer - Chosen by Asker: You might check 2 free sites, Rootsweb and FamilySearch.org.

Now just be very careful about taking as fact everything you see in family trees on any website, free or paid. Most of the information is not documented. You might see different information on the same person by different submitters. Then you will see repeatedly the same information by different submitters without documentation.
A lot of people are copying without verifying. Use the information as clues as to where to get the documentation.

I noticed on FamilySearch there were also some McVoy.

Have you tried just asking a Search Engine for "Voy Family" to see what pops up?
You don't say which Country you are in so I shall have to generalise - right across the US and UK you have Genealogical or Family History Societies with Members researching names, not only in their own Counties but others as well; someone in the area in which you are searching for your ancestors may have a great deal of information about your family already.
Google, for example, East of London Family History Society or Iowa Genealogical Society and check out what the various Societies have to offer in the way of assistance. The web site of the Bristol FHS has a "Members Interests" section so if you have ancestors from the South West of the UK, you can visit, find someone researching your name and contact them.
I live in the Midlands but belong to the Bristol FHS, Devon FHS and Somerset & Dorset FHS because that is where "my lot" originated.
Happy Hunting

http://worldconnect.genealogy.rootsweb.c...
has 121 entries for the surname.

http://ssdi.genealogy.rootsweb.com/cgi-b...
has 71.

The other two answers are better in general terms. This one will show you there IS data to be found on your surname.